computer

[Quinn Dunki] keeps rolling with her 6502 based computer build. This time around she’s added some memory to store the programs, but needed a way to get that code into the device. Above is her solution, a bank of hex switches used to program the 8-bit command and 16-bit address for each line of machine code.

This is a continuation of her Veronica project. The last time we saw it she had hardwired the logic levels for the data bus, but that’s no fun since nothing can actually be computed. [Quinn] picked up an SRAM chip which will store the program. It’s compatible with the 6502’s memory bus, but needs a bit of extra circuitry for her to be able to hand program it with this switch bank. She used some tri-state buffers to switch between connections to the processor, and to the hex switches. This way, she disconnects the RAM from the processor using the buffers, uses the switches and push button to clock in the program, then patches the RAM back into the computer.

If you want people to really be impressed by your projects it’s often better not to have a fully finished look. In this case, we think hooking the stripboard version of FIGnition up to your TV will raise a lot more eyebrows than the PCB version will.

[Julian] put together a guide to building the computer on strip board. He’s using his own Java application for laying out circuits on this versatile prototyping substrate. This tool is worth a look as it may simplify those point-to-point solder prototypes you’ve been agonizing over. You’ll have to do some poking around on his site to gather all of the knowledge necessary to complete the build. Most of the components are easy to source, but unless you have them on hand, you’ll need put in a parts order for the crystal, the ATmega168, the SRAM chip, and the flash memory chip.

For those not familiar, FIGnition is an 8-bit computer with composite TV-out for a display and rudimentary input from the eight momentary push buttons.

The wooden computer case is actually more of a cover in that it uses most of the stock case to house all of the components. It would definitely be a pain, and possibly a fire-hazard, to make a back mounting plate for all the components out of wood. To go along with this, the LCD monitor stand was engineered for a 21″ monitor when the owner of it wasn’t satisfied with the stability of the stock stand. In the end, he ended up building something quite sturdy and nice looking to replace it.

[M. Eric Carr] came up with an interesting build for the 555 contest earlier this year, and we’re pretty sure that it would have kicked the winner of the complex category off the throne if it were completed. Although it’s a few months late, we’re happy to feature at least part of his 555-based computer on Hack A Day.

With his computer tweaked as far as he could imagine, he decided to spruce up his office a bit. In the process, he ended up tweaking his computer just a little bit more. After seeing a build put together by another computer enthusiast, he set off to construct a desk in which he could show off his computer. He spent some time drawing up plans with Google Sketchup and with the help of a friendly neighbor, started construction of his desk/PC case.

The desk is constructed from 3mm thick aluminum, and houses most of his computer’s components under a thick piece of glass. The only portion of the computer that is not enclosed in the desk is the 9-fan radiator he used for his water cooling setup. That part resides in his crawl space, which he connects to his PC via a pair of large water hoses he punched through his tile floor. If you are interested, you can see all 800+ pictures of the build here.

[Mark Fickett] finished his own interesting take on a bicycle computer. These wristwatch-sized devices normally mount to the handlebars and give feedback for current speed, trip distance, and many have options like cadence and heart rate. [Mark’s] has fewer features but it’s clean, simple, and does more than you’d think.

He used some denim to house the electronics which you can see mounted inside the frame of the bike. He’s chosen to use Lilypad components which are Arduino bits meant to be sewn into textiles. We’ve seen a Morse Code keyer using these components and this project is along the same lines. It reads wheel revolutions from a magnetic sensor mounted on the front fork. It has no LCD readout, but when you want to know how far you’ve traveled just press one button and the computer reads it back to in Morse Code played on a tiny piezo buzzer. This package hides one more nice option. Once you arrive home the trip data can be dumped onto a computer for easy graphing. Check out the video after the break to see these features in action.

[Ed Zarick] built a module to control his vehicle which he calls the Jeeputer. The name’s a mash-up of Jeep and Computer; the device itself is a combination of Arduino, character LCD, and a collection of shift registers and relays for interfacing. Watch the video after the break to see what this can do. We were surprised in the beginning when he says that all he has left to do is remove the steering wheel lock and he’ll be able to drive using the interface, but we think he means type in a code to unlock the ignition, not remote control for his car. He then goes on to demonstrate garage door control, power cycling for CB radio, GPS, 110V power inverter, vehicle light control, and much more. This must be the most feature packed car computer we’ve seen so far.